For Phase I of the proposed project, we will conduct initial development of a virtual reality-enhanced DBT treatment for substance abuse disorders in adolescents with dual diagnoses (addiction to any substance or polysubstance use disorder and comorbid mental disorders). We will work with treatment professionals to develop appropriate VR content, engage stakeholders on the practical implications of using VR for treatment (insurance billing, data security, HIPAA privacy, etc.), determine detailed task analysis and identify potential risks through player usability testing, and collect initial qualitative data on patient and clinician reactions to the VR content.